Currently, wireless communication systems such as mobile phone systems and wireless local area networks (WLANs) are widely used. In addition, in the field of wireless communication, in order to further improve a communication speed and a communication capacity, a next-generation communication technology has been continuously discussed. For example, in the 3rd Generation Partnership Project (3GPP) serving as a standardization body, standardization of a communication standard called Long Term Evolution (LTE) and a communication standard called LTE-Advanced (LTE-A) and based on LTE has been completed or is under study.
In such wireless communication systems, a content server provides, to terminals, various kinds of contents such as video contents and music contents in some cases. For example, an intensively deployed large-scale data center is used as a content server, and contents are provided by a cloud service.
However, in a case where a distance from a terminal to the large-scale data center is greater than or equal to a predetermined distance, it takes time, greater than or equal to a predetermined time period, for the terminal to become able to use a content after the terminal transmits a content acquisition request, and a transmission delay occurs in some cases. In some cases, owing to the occurrence of such a transmission delay, it is difficult for the terminal to use the content in real time.
Therefore, in wireless communication systems, a technology called edge computing has been proposed. The edge computing is, for example, a technology in which small-scale data centers are dispersedly arranged at locations whose distances from terminals are shorter than distances thereof from a large-scale data center and the small-scale data centers provide contents. Since contents are distributed from the small-scale data centers, transmission delays are resolved, compared with, for example, a case where contents are distributed from the large-scale data center, and it is possible for the terminals to use the contents in real time.
As technologies for wireless communication, for example, there are the following technologies.
In other words, there is a technology in which, in a case where a terminal performs handover, a source base station transmits, to a target base station, a message including a session state parameter for identifying a state of a session and the target base station transmits, based on the relevant parameter, data packets to the terminal.
According to this technology, it is possible to remove a complexity due to, for example, application states being included in caches.
In addition, there is an access controller. If a switching request to switch from a wireless access network whose service area is discontinuous to another access network is detected, the access controller transfers cached data to the other access network after the switching.
According to this technology, it is possible to provide an access network selection method in, for example, a context of an access network whose service area is discontinuous. As documents of the related art, there are Japanese National Publication of International Patent Application No. 2013-505612 and Japanese Laid-open Patent Publication No. 2006-74741.